'\" te
.\"  Copyright 2006 Sun Microsystems.
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.TH QUNBUFCALL 9F "Jan 16, 2006"
.SH NAME
qunbufcall \- cancel a pending qbufcall request
.SH SYNOPSIS
.nf
#include <sys/stream.h>
 #include <sys/ddi.h>


\fBvoid\fR \fBqunbufcall\fR(\fBqueue_t *\fR\fIq\fR, \fBbufcall_id_t\fR \fIid\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fIq\fR\fR
.ad
.RS 6n
Pointer to \fBSTREAMS\fR queue_t structure.
.RE

.sp
.ne 2
.na
\fB\fIid\fR\fR
.ad
.RS 6n
Identifier returned from \fBqbufcall\fR(9F).
.RE

.SH DESCRIPTION
The \fBqunbufcall()\fR function cancels a pending \fBqbufcall()\fR request. The
argument \fIid\fR is a non-zero identifier of the request to be cancelled.
\fIid\fR is returned from the \fBqbufcall()\fR function used to issue the
cancel request.
.sp
.LP
The \fBqunbufcall()\fR function is tailored to be used with the enhanced
\fBSTREAMS \fRframework interface which is based on the concept of perimeters.
(See \fBmt-streams\fR(9F).) \fBqunbufcall()\fR returns when the bufcall has
been cancelled or finished executing. The bufcall will be cancelled even if it
is blocked at the perimeters associated with the queue. All outstanding
timeouts and bufcalls must be cancelled before a driver close routine can block
and before the close  routine calls \fBqprocsoff\fR(9F).
.SH CONTEXT
The \fBqunbufcall()\fR function can be called from user, interrupt, or kernel
context.
.SH SEE ALSO
.BR mt-streams (9F),
.BR qbufcall (9F),
.BR qtimeout (9F),
.BR quntimeout (9F)
.sp
.LP
\fIWriting Device Drivers\fR
.sp
.LP
\fISTREAMS Programming Guide\fR